Experts believe that the first truly earth-like planet would be discovered in 2013. While in the last few years, a number of exoplanets that possess one or two key traits similar to that of our own world such as size or inferred surface temperature have been discovered, a bona fide alien earth still remains elusive. However, that may change in 2013, according to scientists.

Abel Mendez who runs the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo said he was very positive that the first earth twin would be discovered this year.

The first exoplanet orbiting a sunlike star was discovered in 1995 and since then astronomers have spotted over 800 worlds beyond our own solar system with many more candidates awaiting confirmation through follow-up observations.

NASA's prolific Kepler Space Telescope, for instance, had flagged over 2,300 potential planets since its March 2009 launch, of which only 100 or so had been confirmed to date, but, according to estimates of mission scientists, at least 80 per cent would end up being the real deal.

Mendez is not the only one optimistic about the discovery coming in 2013.

According to Geoff Marcy, planet hunter at the University of California, Berkeley, the first planet with a measured size, orbit and incident stellar flux suitable for supporting life would likely be announced in 2013.